I wanted to build an extension to my Behringer Wing with 24 LINE inputs and 8 LINE outputs without having to use additional power supply over a distance of 20m. So, I got myself a shallow 2U rack case, a 100Ohm DMX XLR cable, 1 Midas DN4816-I (for 16 inputs) and a DN4888 (for 8 additional inputs and 8 outputs). Once I set the switches on the boxes correctly and connected them to the Wing it just worked. The devices are relatively cheap. And though the primarily use StageConnect (which is not seem to much in the wild), there are converters to AES50 and USB available.